1. Field of the Invention
The present invention relates to imaging devices and, more particularly, relates to an imaging device capable of displaying a moving picture image, which is generated by a camera that photographs an object to be inspected, on a mosaic image that is wider in field of view than an actual field of view of the camera.
2. Description of the Related Art
An image mosaic is known in the related art as a technique which creates a sheet of an image with a wide field of view that is wider in field of view than an actual field of view of a camera by assembling a plurality of still images photographed while changing a field of view. In the case of an imaging device such as a digital microscope which photographs a photographic subject enlarged by an objective lens, a field of view can be changed by moving a movable stage on which an object to be inspected is mounted. The image with a wide field of view is called as a mosaic image, and is created by coupling the plurality of still images photographed while changing the field of view in such a manner based on a relative position between images.
For example, in the case of the known imaging device which is equipped with a sensor that detects a position of a movable stage and automatically photographs a photographing range specified by a user, a relative positional relationship between images is judged by control information of the movable stage, and assembly of still images is performed. In such imaging device, when the photographing range is specified and photographing is once started, the photographing range cannot be changed in mid-flow. Furthermore, the position of the movable stage needs to be highly accurately detected; and therefore, there is a problem in that system configuration becomes complicated and high cost.
On the other hand, there is also an imaging device which judges a relative positional relationship between images by pattern matching between the images and assembly of still images is performed. However, there is not an imaging device capable of fetching still images and coupling the same with a mosaic image while making a user confirm a positional relationship between a field of view during photographing and the mosaic image during creation on a display unit. Consequently, there is conceivable an imaging device in which still images are fetched at timing specified by a user and are assembled to a mosaic image while displaying a field of view during photographing as a moving image on the mosaic image. In such imaging device, the image size of the mosaic image varies by the assembly; and therefore, there is a problem in that a part of the mosaic image is not displayed on a screen and a positional relationship between the field of view during photographing and the mosaic image during creation becomes unclear.